1. Field of the Invention
The present invention relates to an apparatus for manufacturing a semiconductor device and more particularly, to a susceptor of an apparatus for manufacturing a semiconductor device.
2. Discussion of the Related Art
A development for a new material has been actively performed in the field and diverse large-scale integrated circuits (LSI) such as ultra large-scale integrated circuits (ULSI) have been developed due to a rapid growth of the new material development. That is, because the new material for forming thin films such as an insulating layer, a semiconductor layer and a conductive layer, which constitute a semiconductor device, has been widely developed in the field, the large-scale integrated circuits (LSI) such as the ultra large-scale integrated circuits (ULSI) are available now. The semiconductor device is generally fabricated through repeated depositing and patterning processes. These processes are accomplished in an apparatus for manufacturing the semiconductor device under vacuum condition.
The apparatus for manufacturing the semiconductor device is classified variously according to a purpose. The apparatus generally includes a processing chamber that is an airtight reaction container, a controller that controls surroundings within the chamber, and a supplying system that stores and provides source materials.
FIG. 1 shows an apparatus for manufacturing a semiconductor device in the related art.
In FIG. 1, the apparatus 10 includes a chamber 20 a supplying part 50. The chamber 20 is an airtight reaction container, and a substrate 1 to be handled is disposed in the chamber 20. The supplying part 50 stores and provides source materials and reaction materials to the chamber 20.
The chamber 20 has an inlet 23, an outlet 24, an injector 22, and a susceptor 30. The inlet 23 is formed in a wall of the chamber 20, and the substrate 1 to be handled comes into and goes out of the chamber 20 through the inlet 23. The outlet 24 is also formed in a wall of the chamber 20 and is connected to a pump “P” that controls the pressure in the chamber 20. Thus, the air within the chamber 20 is exhausted out of the chamber 20 through the outlet 24 by the pump “P”. The injector 22 is disposed on an inner surface of the upper part of the chamber 20 and is connected to the supplying part 50 outside the chamber 20 through a supplying pipe 51. Therefore, source materials and reactive materials from the supplying part 50 are diffused uniformly by the injector 22 after passing through the supplying pipe 51.
The susceptor 30 is disposed in the chamber 20, and the substrate 1 is located on the susceptor 30. The susceptor 30 may be made of graphite or silicon carbide (SiC), and may have a circular shape. The susceptor 30 has a heater 34 therein to accelerate chemical reactions of source materials and reactive materials. Additionally, the susceptor 30 is connected to a first driving instrument 52 such as a motor or an air cylinder, and moves upward and downward by the first driving instrument 52.
A lift pin base 40 is equipped under the susceptor 30, and a plurality of lift pins 42 are formed on the lift pin base 40. The plurality of lift pins 42 pass through the susceptor 30, and the plurality of lift pins 42 raise and lower the substrate 1 during loading or unloading of the substrate 1. The lift pin base 40 is connected to a second driving instrument 54 such as a motor or an air cylinder. Therefore, the lift pin base 40 and the plurality of lift pins 42 move upward and downward by the second driving instrument 54.
In the apparatus of FIG. 1, the substrate 1 is carried into the chamber 10 via the inlet 23 and is loaded on the susceptor 30 using the plurality of lift pins 42. Next, the air in the chamber 10 is exhausted through the outlet 24 by the pump “P”. Source materials and reactive materials in the supplying part 50 are transmitted to the chamber through the supplying pipe 51, and are injected into the chamber 10 by the injector 22. The source materials and reactive materials react by applying electrical energy or thermal energy, so that a thin film is deposited on the substrate 1 or a thin film deposited on the substrate 1 is patterned.
FIG. 2 is a view of magnifying the susceptor of the apparatus for manufacturing a semiconductor device of FIG. 1. As stated above, the susceptor 30 has the heater 34 in order to speed up depositing and patterning of the thin film and in order to stabilize the depositing and patterning processes. Additionally, the lift pin base 40 of FIG. 1, on which a plurality of lift pins 42 are formed vertically with respect to the lift pin base 40, is arranged under the susceptor 30. The plurality of lift pins 42 pass through the susceptor 30. The susceptor 30 and the lift pin base 40 are connected to the first and second driving instruments 52 and 54 of FIG. 1, respectively, and move upward and downward by the first and second driving instruments 52 and 54.
During a loading step when the substrate 1 is put on the susceptor 30 in the chamber 20 or during an unloading step when the substrate 1 is taken out the chamber 20, the lift pin base 40 rises by the second driving instrument 52 of FIG. 2. Then, the plurality of lift pins 42 are protruded over the upper surface of the susceptor 30 and lift up the substrate 1. Therefore, loading and unloading of the substrate 1 get easy.
FIG. 3 is a cross-sectional view along the line III—III of FIG. 2. In FIG. 3, the susceptor 30 of the related art is composed of an upper part 32, a lower part 33, and a heater 34 disposed between the upper and lower parts 32 and 33. The upper part 32, the lower part 33, and the heater 34 have first, second, and third lift pin holes 32a, 33a, 34a that the lift pin 42 passes through, respectively. The lift pin 42 has a hung portion 42a and the first lift pin hole 32a has a hanging portion 32b on the top. The hanging portion 32b corresponds to the hung portion 42a and is hollow. The hanging portion 32b has a wider width than the hung portion 42a and the other portion of the first lift pin hole 32a except for the hanging portion 32b has a narrower width than the hung portion 42a. 
While the lift pin 42 has the lowest position as shown by a dotted line, that is, while a process of handling the substrate 1 of FIG. 1 is going on, the hung portion 42a is located in the hanging portion 32b. Therefore, the substrate 1 sticks to the susceptor 30, and is dealt with. Meanwhile, when the substrate 1 is loaded or unloaded, the lift pin 42 rises through the susceptor 30 and raises the substrate 1. Thus, the substrate 1 is situated on the hung portion 42a of the lift pin 42 and is carried out of the chamber 10.
However, in the susceptor of the related art, the heater 34 is oxidized easily. The source materials and the reactive materials include an oxide having oxygen (O2) or ozone (O3). The oxide permeates the susceptor 30 through the second lift pin hole 33a along the path shown by the arrow in FIG. 3, and oxidizes the heater 34. The heater 34 is oxidized very more near the third lift pin hole 34a of the heater 34, which is close by the second lift pin hole 33a. Accordingly, the heater 34 has a different temperature partially, and the substrate 1 is not heated uniformly. The thin film to be deposited or to be patterned has bad properties.
Moreover, if the heater 34 is oxidized excessively, the heater 34 is not operated normally, and the manufacturing process is made impossible. The oxidation of the heater 34 lowers the productivity of the semiconductor device, and has an affect on uniformity, critical dimension, profile, repeatability, etc. of the semiconductor device.